To improve the reliability and flexibility of the protocol, we introduce
multiplexing over peer connections. This involves a new `Frame` type
that carries a stream-id and payload.
Three stream types are made available:
1. Control
2. Gossip
3. Git
This change brings the following improvements:
* Removed need to queue fetch requests
* Removed need to queue gossip messages
* Removed need for `Fetch` and `FetchOk` messages
* Service doesn't need to know about inbound fetches
* Removed one round-trip for fetch negotiation
* Removed special `done` git packet
* Removed session logic and state around Git/Fetch protocols
* Removed code around upgrading/downgrading transport
* Worker in responder mode is able to process any number of fetches
* Connections support any number of concurrent fetches
We had to introduce a few extra things however to make it all work:
* A `VarInt` type for variable-length integers, since we want the frames
to be lightweight.
* A custom "tunnel" implementation, since we couldn't use the existing
one anymore.
Overall the change removes more complexity than it adds, while improving
the protocol along the way.
The One variant caused many paint points for fetching logic, where it
was not necessary. It was only constructed in one place, which could
be replaced by using the variant that holds a set of keys.
Remove the Namespaces::One variant and rename Namespaces::Many to
Namespaces::Trusted.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
When a repository does not yet exist during a fetch, i.e. a clone,
then only delegates are being fetched.
Augment Namespaces::Many to hold the trusted and optional delegate peers
separately. Doing so allows the construction of the variant without
the repository existing, but tracking relationships existing.
This variant can then be used to build refspecs for both the trusted
peers and delegates when doing a cloning fetch.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
First, we make sure to always attempt reconnection to persistent peers,
no matter the reason.
Second, we don't re-attempt connections when an inbound peer
disconnects. This minimizes the chance of connections crossing.
Third, we clean up `session::Error`, and don't use it to signal a
missing session, since it doesn't really belong there.
This change ensures that on `Subscribe`, we only relay the latest
announcement of each node, per announcement category.
Previously, we would relay all announcement, while only the last one
was relevant.
It's not a good idea to have fallible operations run after `FetchOk`
is received, since there's no easy way to communicate the error
to the remote at that point. What would then happen is that the fetch
just "hangs", since nothing is there to cancel it.
Hence, we compute namespaces earlier in the process, and store the
namespaces in the session. If there is a failure, the fetch is
never initiated.
It was possible to trigger multiple connection attempts to the same
peer, since we didn't track connection attempts that hadn't yet
returned to the service via `Service::attempted`.
With this change, we add an extra `Initial` state to sessions, so
that redundant connections are not attempted when one is already under
way.
It's possible for a peer to disconnect before responding with `FetchOk`.
In that case, we make sure to return to any pending fetch request with
an error.
To determine the correct Namespaces to use, the repo Policy and Scope
are consulted.
If the policy is Block then this is a failure state and is reported to
the other end.
Otherwise, if the policy is Track, then the scope is checked. For the
Trusted Scope then the Namespaces should consist of all tracked nodes
and delegates for the given repository. However, the repository might
not exist and so it is necessary for the whole repository to be
fetched.
For the All Scope, all Namespaces are fetched.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
The fetch implementation will potentially fetch the local operator's
remote, which is unnecessary and could result in deleted data.
Fix this by threading the local operator's public key and add an
ignore refspec to the fetch arguments, i.e.
^refs/namespaces/<local>/*
The implementation also strictly fetches all or one namespace. This is
improved upon by introducing a new variant for specifying a set of
namespaces.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
Instead of returning tuples for `repo_entry` and `node_entry`, return
the `Repo` and `Node` types, respectively.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
The tracking configuration has no way of consulting for a configured
scope.
This change allows the storing of this scope inside the tracking
`Config` -- currently unused.
The default Scope is chosen as Trusted, so that nodes do not
implicitly track any other node. If this behaviour is desired -- for
example, for seed nodes -- then All should be chosen.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
The DelegatesOnly scope is very limited and causes more confusion than
it solves.
The Trusted scope subsumes DelegatesOnly since it implies delegates
along with any tracked nodes. This feels more natural to use and so
DelegatesOnly is removed -- leaving only Trusted and All.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
Previously the alias field was simply a string which could possibly be
empty. Some checks were made to see if this string was empty.
Instead, make the logic more obvious by making the alias field
optional.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
A fetch is a client-server interaction and so there are two sides to
this interaction. These sides are generally referred to as receive --
the client side -- and upload -- the server side.
The `Fetch` type indicated whether it was doing a receive or upload by
using a field `initiated: bool`. However, this can be confusing when
you pair it with the `namespaces: Namespaces` field, since only the
receive side should be sending what refspecs it wants and the upload
side responds with those matching refspecs.
A better way to represent this is using an enum for which direction
the fetch is being considered, where the receive side contains the
Namespaces. To borrow from Noise, the variant names are 'Initiator'
for the client and 'Responder' for the server.
The resulting code then makes decisions based on what variant of the
enum was passed.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
It is possible for a pair of nodes to concurrently ask each other
to fetch some repo. These "crossing" requests are problematic,
because the nodes end up waiting for each other to reply, and
the reply never comes.
With this change, the node pair agrees on proceeding with one of
the fetches, while canceling the other.
The routing function for Node was not implemented and there were no
functions for getting any tracking information.
This implements routing, tracked_repos, and tracked_nodes. To
accomplish this it was necessary to add associated types to the
Handler trait so that implementations could differ in the types they
use for returning this data, i.e. the control socket needs to use a
channel while the Node needs to return serializable data.
Currently, the Node uses a `Vec` but it would be more beneficial to
return an Iterator directly to ensure we are not always hitting the
heap.
To allow for the tracking types to be used across radicle-node (the
crate) and in radicle::node (the module), it was necessary to move
the types to the common place, i.e. radicle::node. At the same time,
new structs were added to make it easier to refer to tracked repos vs
tracked nodes.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
Previously, the seeds information would only consist of the connected
NodeIds.
Improve on this by adding any disconnected and fetching seeds as
well. A seed can either be disconnected, connected, or fetching --
where fetching implies connected.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
When a specific tracking policy isn't found, we allow setting a default.
To preserve existing behavior, the default is `Block`, ie. if a node
isn't tracked explicitly, it is blocked.
However, this change allows for using `Track` as the default, which
is a way to track everything without having to know the entities in
advance.
We weren't updating the sessions map when a persistent peer
was re-attempted. It would then panic when `connected` was called,
because the state would be `Disconnected`.
Rust 1.67 was announced[0]. Update the necessary files for running
1.67 and fix the clippy suggestions for string interpolation.
[0]: https://blog.rust-lang.org/2023/01/26/Rust-1.67.0.html
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
Alexis Sellier
Fintan Halpenny
Han Xu
xphoniex
Alexis Sellier